Motors racing after hand catch

[mroek]

When hand catching my Mini 3, I usually just keep the throttle stick fully down, which should stop the motors after 3 seconds, according to DJI. It usually does, but sometimes it takes longer, and today the motors just kept running at full blast, so I had to do the turnover manouver to stop it. It was very windy, and the drone had really been struggling, but why did it not stop the motors while I held the stick fully down?

I see that DC Rainmaker actually recommends the turnover move to stop the motors, but I read somewhere (can't find it again now), that somebody claimed that manouver could be harmful to the drone. From a technical standpoint, I can't understand why, as the sensors should not in any way suffer from this, and the motors are shut off immediately. Holding a drone that is running full blast on the motors is not really great, even if it's not difficult to hold the Mini 3. A bigger and more powerful drone is far worse, of course.

 

[scro]

Sounds like the drone didn't realise it had "landed" and tried to maintain or gain altitude. Did you keep your hand still after the catch or "pull" the drone downwards a bit? Could have tricked the drone into thinking it had further to go before landing. Still, holding the down stick down should eventually convince it that it's landed.

Using the flip-over method to shut the motors off is quite ok for the drone. The motors are designed to run quite happily and safely at their set maximum speed so having them briefly spin up to that speed is well within their design. The motors don't even reach full speed if you flip it over quickly.

 

[Kilrah]

You probably weren't steady enough after catching. The drone won't mind being turned over, it's just a little sketchy safety-wise especially with the more powerful machines.

 

[Coskier]

I tried to flip the Mavic 3 once, way too powerful to do it safely.

 

[globetrotterdrone]

Not had that issue, hand catching every time.
It lands very smoothly, a bit delayed compared to my Mavic 2 Pro, which ignored my hand after 1 s, the Mini 3 Pro takes about 3 s but after landing, motors are properly shutting down.

 

[EyesWideShut]

Was your hand open and flat and steady for the drone to land on or were you gripping the drone? As others have suggested, if you lower your hand the drone will speed up to maintain it's altitude as it going into landing mode. If you are gripping it and your hand lowers an inch or so, it will fight you to maintain that altitude. Just raise your hand and it will be happy and stop fighting and then go back into the 3 second landing mode if you are holding the stick down.
Give it a test when hand landing next time by gripping it and lowering your hand slightly, when it speeds up, just release and let it go. If it loves you it will return...

 

[mroek]

Sounds like the drone didn't realise it had "landed" and tried to maintain or gain altitude. Did you keep your hand still after the catch or "pull" the drone downwards a bit? Could have tricked the drone into thinking it had further to go before landing. Still, holding the down stick down should eventually convince it that it's landed.

Using the flip-over method to shut the motors off is quite ok for the drone. The motors are designed to run quite happily and safely at their set maximum speed so having them briefly spin up to that speed is well within their design. The motors don't even reach full speed if you flip it over quickly.

I agree the drone must have thought it should still be flying. I did not move my hand, but I did grip the drone (as I said, it was windy, and just letting it land flat on my hand wasn't something I'd want to try in that situation). It did run at full speed for maybe 2-3 seconds before I realized it really wasn't going to obey my fully down stick, but I'm sure it didn't cause any harm. I flew it inside the house right after, just to drain the battery down a little.

Was your hand open and flat and steady for the drone to land on or were you gripping the drone? As others have suggested, if you lower your hand the drone will speed up to maintain it's altitude as it going into landing mode. If you are gripping it and your hand lowers an inch or so, it will fight you to maintain that altitude. Just raise your hand and it will be happy and stop fighting and then go back into the 3 second landing mode if you are holding the stick down.
Give it a test when hand landing next time by gripping it and lowering your hand slightly, when it speeds up, just release and let it go. If it loves you it will return...

No, I did grip it (as I usually do without this issue). I just feel more comfortable doing that than letting it land on my palm, and especially in these windy conditions.

I'm pretty sure I didn't lower my hand, but I'll keep your advice in mind and try to explicitly raise my hand (while still holding down stick) the next time.

Ultimately, flipping it over to stop it should also be OK, as others have said.

 

[jimlips]

I've found it works better (if you are grabbing it, rather than open-palm), to actually make contact lower to the ground (say, chest-level). Once you make contact, move your hand/arm UP, the drone will sense this, and actually lower the speed of the motors and stop.

 

[twickers14]

Very interesting. I have never tried to hand catch my MA2 as, although I managed to catch my Spark a couple of times, I successfully scythed a decent slice of my right index finger off (all mended) and thought “why bother”. Also what technique do people use-I struggle to whack the left stick down holding the RC in my left hand as I concentrate on providing a flat, no fingers in the way, landing pad for the drone.

 

[globetrotterdrone]

@twickers14
That's how I do it since the M2P without any problem.
First flat hand and when the drone slowly descends and is within my hand, grab it, reverse for start (I put the controller on my bag and swipe with the left hand while holding it with the right).

It's really intuitive and safe.

These are the 2 videos I refer to:

 

[JimSteadman]

I have repeatedly hand caught my Mini and Mavic Air, but find that if it is windy, it is more difficult and, for me at least, was an unpleasant experience. No permanent damage, but I did bark up 3 fingers in a nano-second. No damage to the props or the drone, but I will affirm that your fingers have a generous blood supply, which can drip inside your car as you drive home with one hand wrapped in a paper towel.

 

[mroek]

I have repeatedly hand caught my Mini and Mavic Air, but find that if it is windy, it is more difficult and, for me at least, was an unpleasant experience. No permanent damage, but I did bark up 3 fingers in a nano-second. No damage to the props or the drone, but I will affirm that your fingers have a generous blood supply, which can drip inside your car as you drive home with one hand wrapped in a paper towel.

Ouch, that sounds unpleasant. I have never caught my fingers in the props on a drone, but I'd rather avoid it. However, hand catching is useful enough that I will run the risk when necessary.

About the racing motors, I tried the advice of lifting the drone after catch, and it worked perfectly on one occasion, but on the next it didn't. I can't seem to find the pattern here. I suspect maybe I need to grip it further towards the front, so that I fully cover the IR-sensors that look downward.